From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph of engine RPM versus MPH for various gears and tyre specifications.
| Identifier | ExFiles\Box 90a\2\ Scan273 | |
| Date | 28th July 1934 guessed | |
| F.R. HALLS CHASSIS R.P.M. AT 60 M.P.H. 5.50 x 18 TYRES TOP 2803 3RD 3244 2ND 4146 30 M.P.H. 1ST 2635 5.25 x 18 TYRES TOP 2687 3RD 3110 2ND 4240 30 M.P.H. 1ST 2695 TYRE CIRCUMFERENCE EFFECTIVE AT 35 LBS. 5.50.18 - 92.3" TYRE CIRCUMFERENCE EFFECTIVE AT 35 LBS. 5.25.18 - 88.5" ROAD WHEEL REVS MILE. 5.50 TYRES. = 701.9 ROAD WHEEL REVS MILE. 5.25" TYRES. = 717.79 AXLE RATIO 11 x 41 - 3.72 : 1 LEGEND: 5.50" TYRES (Solid Line) 5.25" TYRES (Dashed Line) AXIS: M.P.H. (Y-Axis) R.P.M. (X-Axis) GEARS: TOP 3RD 2ND 1ST F.D. | ||